Chapter 15 Digital Darkroom Basics
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Once the
Color Replacement
tool is selected, click
on the foreground color in the toolbox to open
a color palette. Select the desired replacement
color by clicking OK. The
Color Replacement
tool brush is shown as a circle with a crosshair
in the center. Placing the crosshair over the color
to be replaced and clicking will change the color
under the brush circle, Figure 15-35. Brush size
and sensitivity (tolerance) can be changed on the
Options
bar.
Figure 15-33. The hue slider can be used to make
dramatic shifts in the color of a red flower such as this
nasturtium. A—Sliding to the left shifts the color to a
deep blue (the original color is displayed in the small
image on both the
History
palette and the
Background
layer in the
Layers
palette.). B—Sliding the control to the
right shifts the hue to yellow.
A
B
Figure 15-34. The preview window of the
Replace
Color
dialog box shows (in white) the areas of color
selected for replacement. The selected color is shown in
the
Color
square above the preview; the
Result
square
below the preview shows the color selected by using the
Hue, Saturation, and
Lightness
sliders. In this example,
the selected color in the water lily was a deep pink; the
replacement color is a blue-violet.
Converting Color to
Monochrome
For dramatic effect or other reasons, it is
sometimes desirable to change a color image to a
monochrome (single-color; typically black-and-
white) image. There are several ways to achieve
this result:
• Mode conversion to grayscale
• Choosing one of the color channels as the
grayscale source
• Removing color (desaturation)
• Using the
Channel Mixer
command.
• Creating a
Black & White
adjustment layer.
When an image is converted from a color mode
to grayscale mode, all the color information is
thrown away. The three color channels (red, green,
blue) are merged into a single grayscale channel.
The major drawback to this form of conversion is
that the resulting image is often somewhat flat and
lacking in contrast (especially local contrast). The
problem occurs because quite different colors (some
shades of red and green, for example) have very
similar brightness values. When converted from